An image forming apparatus includes a sheet feed portion and a drive control portion. The sheet feed portion includes a conveying member which is provided more on an upstream side of a conveying direction of a sheet than a transfer position of a toner image on a conveying path of the sheet that passes through the transfer position, and feeds the sheet from a sheet feed position that is more on a downstream side of the conveying direction than the conveying member on the conveying path. The drive control portion drives a stepping motor used for driving the conveying member such that the sheet reaches the sheet feed position at a time a next sheet feed timing by the sheet feed portion arrives.
Legal claims defining the scope of protection, as filed with the USPTO.
. An image forming apparatus, comprising:
. A drive control method executed in an image forming apparatus including a transfer portion which transfers a toner image onto a sheet, a sheet feed portion which includes a conveying member which conveys, on a conveying path of the sheet that passes through a transfer position of the toner image by the transfer portion, the sheet at a position that is more on an upstream side of a conveying direction of the sheet than the transfer position, and feeds the sheet at a predetermined sheet feed cycle from a sheet feed position that is more on a downstream side of the conveying direction than the conveying member on the conveying path, and a stepping motor which drives the conveying member, the drive control method comprising:
Complete technical specification and implementation details from the patent document.
This application is based upon and claims the benefit of priority from the corresponding Japanese Patent Application No. 2024-073310 filed on Apr. 30, 2024, the entire contents of which are incorporated herein by reference.
The present disclosure relates to an image forming apparatus and a drive control method.
An image forming apparatus that uses electrophotography includes a transfer portion and a sheet feed portion. The transfer portion transfers a toner image onto a sheet. The sheet feed portion includes a conveying member which conveys, on a conveying path of the sheet that passes through a transfer position of the toner image by the transfer portion, the sheet at a position that is more on an upstream side of a conveying direction of the sheet than the transfer position, and feeds the sheet at a predetermined sheet feed cycle from a sheet feed position that is more on a downstream side of the conveying direction than the conveying member on the conveying path.
Further, an image forming apparatus including a stepping motor which drives the conveying member is known as the related art. In this image forming apparatus according to the related art, drive of the stepping motor is stopped until a next sheet feed timing by the sheet feed portion arrives since a timing at which the sheet has reached the sheet feed position.
An image forming apparatus according to an aspect of the present disclosure includes a transfer portion, a sheet feed portion, a stepping motor, a detection processing portion, and a drive control portion. The transfer portion transfers a toner image onto a sheet. The sheet feed portion includes a conveying member which conveys, on a conveying path of the sheet that passes through a transfer position of the toner image by the transfer portion, the sheet at a position that is more on an upstream side of a conveying direction of the sheet than the transfer position, and feeds the sheet at a predetermined sheet feed cycle from a sheet feed position that is more on a downstream side of the conveying direction than the conveying member on the conveying path. The stepping motor drives the conveying member. The detection processing portion detects the sheet conveyed by the conveying member at a position that is more on the upstream side of the conveying direction than the sheet feed position on the conveying path. The drive control portion drives the stepping motor such that the sheet reaches the sheet feed position at a time a next sheet feed timing by the sheet feed portion arrives based on a detection timing of the sheet by the detection processing portion.
A drive control method according to another aspect of the present disclosure is executed in an image forming apparatus including a transfer portion which transfers a toner image onto a sheet, a sheet feed portion which includes a conveying member which conveys, on a conveying path of the sheet that passes through a transfer position of the toner image by the transfer portion, the sheet at a position that is more on an upstream side of a conveying direction of the sheet than the transfer position, and feeds the sheet at a predetermined sheet feed cycle from a sheet feed position that is more on a downstream side of the conveying direction than the conveying member on the conveying path, and a stepping motor which drives the conveying member, and includes a detection step and a drive control step. The detection step includes detecting the sheet conveyed by the conveying member at a position that is more on the upstream side of the conveying direction than the sheet feed position on the conveying path. The drive control step includes driving the stepping motor such that the sheet reaches the sheet feed position at a time a next sheet feed timing by the sheet feed portion arrives based on a detection timing of the sheet in the detection step.
This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description with reference where appropriate to the accompanying drawings. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Furthermore, the claimed subject matter is not limited to implementations that solve any or all disadvantages noted in any part of this disclosure.
Hereinafter, an embodiment of the present disclosure will be described with reference to the attached drawings. It is noted that the following embodiment is an example of embodying the present disclosure and does not limit the technical scope of the present disclosure.
First, a configuration of an image forming apparatusaccording to the embodiment of the present disclosure will be described with reference toand. Herein,is a cross-sectional view showing the configuration of the image forming apparatus.
The image forming apparatusis a printer that forms an image on a sheet using electrophotography. It is noted that the present disclosure can be applied to a facsimile apparatus, a copying machine, a multifunction peripheral, and the like that form an image on a sheet using electrophotography.
As shown inand, the image forming apparatusincludes an image forming portion, a sheet conveying portion, an operation display portion, a communication portion, a storage portion, a control portion, a first sheet feed control portion, and a second sheet feed control portion.
The image forming portionforms an image on a sheet using electrophotography based on image data input from an external information processing apparatus such as a personal computer.
The sheet conveying portionconveys a sheet on which an image is to be formed by the image forming portion.
The operation display portionis a user interface of the image forming apparatus. The operation display portionincludes a display portion and an operation portion. The display portion displays various types of information in response to control instructions from the control portion. For example, the display portion is a flat panel display such as a liquid crystal display. The operation portion is used to input various types of information to the control portionaccording to user operations. For example, the operation portion includes operation keys and a touch panel.
The communication portionis a communication interface that executes wired or wireless data communication with the external information processing apparatus.
The storage portionis a nonvolatile storage device. For example, the storage portionis a nonvolatile memory such as a flash memory.
The control portioncollectively controls the image forming apparatus. As shown in, the control portionincludes a CPU, a ROM, and a RAM. The CPUis a processor that executes various types of arithmetic processing. The ROMis a nonvolatile storage device in which information such as control programs for causing the CPUto execute various types of processing is stored in advance. The RAMis a volatile or nonvolatile storage device that is used as a temporary storage memory (working area) for the various types of processing to be executed by the CPU. In the control portion, the CPUexecutes the various control programs stored in advance in the ROM. Thus, the control portioncollectively controls the image forming apparatus.
The first sheet feed control portioncontrols sheet feed operations by a first sheet feed portion(see) of the sheet conveying portion. The first sheet feed control portionis constituted of an electronic circuit such as an integrated circuit (ASIC, DSP).
The second sheet feed control portioncontrols sheet feed operations by a second sheet feed portion(see) of the sheet conveying portion. The second sheet feed control portionis constituted of an electronic circuit such as an integrated circuit (ASIC, DSP).
Next, configurations of the image forming portionand the sheet conveying portionwill be described with reference toand.
As shown in, the image forming portionincludes a photoconductor drum, a charging device, a laser scanning unit, a developing device, a toner container, a transfer roller, a cleaning device, a fixing device, and a sheet discharge tray.
The photoconductor drumis provided to be rotatable in a direction indicated by an arrow shown in. The charging devicecharges a circumferential surface of the photoconductor drum. The laser scanning unitirradiates light that is based on image data onto the circumferential surface of the photoconductor drumcharged by the charging device. An electrostatic latent image is formed on the circumferential surface of the photoconductor drumby the laser scanning unit.
The developing deviceuses toner to develop the electrostatic latent image formed on the circumferential surface of the photoconductor drum. A toner image is formed on the circumferential surface of the photoconductor drumby the developing device. The toner containersupplies toner to the developing device. The transfer rollertransfers the toner image formed by the developing deviceonto a sheet conveyed by the sheet conveying portion. The cleaning devicecleans the circumferential surface of the photoconductor drumafter the toner image is transferred by the transfer roller. The transfer rolleris an example of a transfer portion according to the present disclosure.
The fixing devicefixes the toner image that has been transferred onto the sheet by the transfer rolleronto the sheet. The sheet onto which the toner image has been fixed by the fixing deviceis discharged onto the sheet discharge tray.
As shown in, the sheet conveying portionincludes a sheet feed cassette, a first conveying path, a second conveying path, a third conveying path, a fourth conveying path, and a fifth conveying path. It is noted that in, the first conveying path, the second conveying path, the third conveying path, the fourth conveying path, and the fifth conveying pathare indicated by thick solid lines.
The sheet feed cassettestores sheets on each of which an image is to be formed by the image forming portion. For example, the sheet feed cassettestores sheets such as a paper sheet, coated paper, a postcard, an envelope, and an OHP sheet.
The first conveying pathis a movement path of the sheet that is provided from the sheet feed cassetteto a junction position P(see) inside a housing of the image forming apparatus. The first conveying pathis connected to the second conveying pathat the junction position P. On the first conveying path, the sheet is conveyed in a first conveying direction Dshown in.
The second conveying pathis a movement path of the sheet that is provided from the junction position Pto a branching position P(see) inside the housing of the image forming apparatusvia a transfer position of the toner image by the transfer rollerand the fixing device. The second conveying pathis connected to the third conveying pathand the fourth conveying pathat the branching position P. On the second conveying path, the sheet is conveyed in a second conveying direction Dshown in.
The first conveying pathis provided with the first sheet feed portionshown in.
The first sheet feed portionincludes a first upstream-side rollerA, a first downstream-side rollerB, and a first sheet sensorC shown in. The first sheet feed portionalso includes a first stepping motorD shown in.
As shown in, the first upstream-side rollerA and the first downstream-side rollerB are arranged next to each other along the first conveying path. The first upstream-side rollerA is arranged more on an upstream side of the first conveying direction Dthan the first downstream-side rollerB. The first upstream-side rollerA and the first downstream-side rollerB convey a sheet that has been taken out of the sheet feed cassettein the first conveying direction D.
As shown in, the first sheet sensorC is provided between the first upstream-side rollerA and the first downstream-side rollerB on the first conveying path. The first sheet sensorC detects the sheet conveyed by the first upstream-side rollerA. For example, the first sheet sensorC is a reflective or transmissive optical sensor.
The first stepping motorD drives the first upstream-side rollerA and the first downstream-side rollerB.
On a first sheet feed path (an example of a conveying path according to the present disclosure) that passes through a transfer position of a toner image by the transfer roller, the first upstream-side rollerA and the first downstream-side rollerB are arranged more on the upstream side of the conveying direction of the sheet than the transfer position. The first sheet feed path is a sheet feed path of the sheet for forming an image on a front surface of the sheet, and is constituted of the first conveying pathand the second conveying path. The first upstream-side rollerA and the first downstream-side rollerB are an example of a conveying member according to the present disclosure.
The first sheet feed portionfeeds the sheet from a first sheet feed position Pshown in. As shown in, the first sheet feed position Pis a position that is more on the downstream side of the conveying direction of the sheet than the first upstream-side rollerA and the first downstream-side rollerB on the first sheet feed path.
Specifically, when one-sided image forming processing for forming an image on one side of a sheet using the image forming portionis executed, the first sheet feed portionfeeds a sheet from the first sheet feed position Pat a predetermined first sheet feed cycle.
In addition, when double-sided image forming processing for forming images on both sides of a sheet using the image forming portionis executed, the first sheet feed portionfeeds a sheet from the first sheet feed position Pat the first sheet feed cycle before a sheet is fed to the second sheet feed portion(see).
Furthermore, when the double-sided image forming processing is executed, after a sheet is fed to the second sheet feed portion(see), the first sheet feed portionfeeds a sheet from the first sheet feed position Pat a second sheet feed cycle that is twice the first sheet feed cycle.
The third conveying pathis a movement path of the sheet that is provided from the branching position Pto the sheet discharge tray. On the third conveying path, a sheet having an image formed on one or both sides thereof is conveyed in a third conveying direction Dshown in.
The fourth conveying pathis a movement path of the sheet that is provided from the branching position Pto a sheet discharge portA (see) formed at an upper portion of the housing of the image forming apparatus. On the fourth conveying path, the sheet having an image formed on a front surface thereof is conveyed in a fourth conveying direction Dshown in.
The sheet discharge portA is provided with a reverse conveying rollerB shown in. The reverse conveying rollerB switches back the sheet and supplies the sheet to the fifth conveying path. Specifically, the reverse conveying rollerB causes the sheet protrude from the sheet discharge portA to the outside of the housing of the image forming apparatusuntil nipping an end portion of the sheet on the upstream side of the fourth conveying direction D(rear end). Then, the reverse conveying rollerB switches back the sheet by rotating in a reverse direction at a timing at which the rear end of the sheet is nipped. It is noted that a sheet support trayC (see) that supports the sheet protruding from the sheet discharge portA is formed on an upper surface of the housing of the image forming apparatus.
The fifth conveying pathis a movement path of the sheet that is provided from the reverse conveying rollerB to the junction position P(see). On the fifth conveying path, the sheet having an image formed on a front surface thereof is conveyed in a fifth conveying direction Dshown in.
The fifth conveying pathis provided with the second sheet feed portionshown in.
The second sheet feed portionincludes a second upstream-side rollerA, a second downstream-side rollerB, and a second sheet sensorC shown in. The second sheet feed portionalso includes a second stepping motorD shown in.
As shown in, the second upstream-side rollerA and the second downstream-side rollerB are arranged next to each other along the fifth conveying path. The second upstream-side rollerA is arranged more on the upstream side of the fifth conveying direction Dthan the second downstream-side rollerB. The second upstream-side rollerA and the second downstream-side rollerB convey the sheet conveyed from the reverse conveying rollerB in the fifth conveying direction D.
As shown in, the second sheet sensorC is provided between the second upstream-side rollerA and the second downstream-side rollerB on the fifth conveying path. The second sheet sensorC detects the sheet conveyed by the second upstream-side rollerA. For example, the second sheet sensorC is a reflective or transmissive optical sensor.
The second stepping motorD drives the second upstream-side rollerA and the second downstream-side rollerB.
On a second sheet feed path (an example of the conveying path according to the present disclosure) that passes through the transfer position of the toner image by the transfer roller, the second upstream-side rollerA and the second downstream-side rollerB are arranged more on the upstream side of the conveying direction of the sheet than the transfer position. The second sheet feed path is a sheet feed path of the sheet for forming an image on a back surface of the sheet, and is constituted of the fifth conveying pathand the second conveying path. The second upstream-side rollerA and the second downstream-side rollerB are an example of the conveying member according to the present disclosure.
The second sheet feed portionfeeds a sheet from a second sheet feed position Pshown in. As shown in, the second sheet feed position Pis a position that is more on the downstream side of the fifth conveying direction Dthan the second upstream-side rollerA and the second downstream-side rollerB on the second sheet feed path. In the image forming apparatus, the second sheet feed position Pis determined such that a distance from the first sheet feed position Pon the first sheet feed path to the transfer position becomes equal to a distance from the second sheet feed position Pon the second sheet feed path to the transfer position.
Specifically, when the double-sided image forming processing is executed, the second sheet feed portionfeeds sheets from the second sheet feed position Pat the second sheet feed cycle.
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October 30, 2025
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